- "Once we step through, we might not be able to come back. We may never see our parents again. There's no turning back. But this may be our only chance. We can't let fear stop us! I'm not afraid of the darkness"
- —Riku to Sora
Riku is the Protagonist in the Kingdom Hearts series. Riku lives on Destiny Islands. He is the best friend of Sora and Kairi. Riku is five years old during Kingdom Hearts Birth by Sleep, fifteen during the events of Kingdom Hearts and Kingdom Hearts: Chain of Memories, and sixteen during the events of Kingdom Hearts 358/2 Days, Kingdom Hearts II and Kingdom Hearts 3D: Dream Drop Distance. Riku's name is derived from the Japanese word for "Land".
Riku's story begins a number of years before the night of the Heartless invasion on Destiny Islands. He and Sora have always trained and pushed each other to make one another stronger. In Kingdom Hearts Birth by Sleep, Terra can already sense Riku's potential, and asks why Riku wants to leave his island. Riku tells Terra that Master Xehanort left the island long ago, and visited other worlds. Riku states that he would like to leave his world too in order to become strong enough to protect his friends and everything he holds dear. During their conversation, Terra sees a vision of a white-haired man who then transforms into Riku's future self in Kingdom Hearts II. This convinces him to choose Riku as his successor, and lets Riku hold his Keyblade to test his strength. He convinces Riku to keep their conversation a secret to preserve the world order.
He and Sora later encounter Aqua, who finds their friendship similar to that of hers and Terra's and Ven's, and asks Sora to protect Riku if he ever loses his path.
After the ending credits, Riku and Sora are seen resting on a beach under a starry night. When they are ready to go home, Riku sees Sora's sudden look of sadness and says that perhaps someone from another world is feeling sad somewhere and suggests for him to try and reach out to him. After Sora reached out to Ven, they both look up at the starry sky.
Between Kingdom Hearts Birth by Sleep and Kingdom HeartsEdit
One night, there is a meteor shower and a mysterious girl appears on the islands from another, far off world now stuck on the Destiny Islands, with no way to return to her home. Riku, Sora, and Kairi quickly forge a powerful friendship. Soon after Kairi's arrival, Riku and Sora go to the secret place, a small cave that they frequently explored. While there, the two spot a mysterious door, though neither one can find a way to open it. The two decide to leave, but Riku manages to get a glimpse of Destiny Islands' Keyhole. In an Ansem report, this world is revealed to be Radiant Garden. From this day on Riku became obsessed with finding out what lies beyond the door, wondering if it could perhaps be a passageway to another world, such as Kairi's.
Riku appears as a cool and collected 15-year-old. He and his best friends Sora and Kairi live on the Destiny Islands. The three spend their days constructing a raft and gathering supplies, so that they might one day set out and search for other worlds. He and Sora share a fierce but good natured rivalry, competing over who is stronger in battle, among other things. Despite the fact that their arguments are of good intention, Riku is known to irritate Sora by being a bit of a sore loser and (in the original Kingdom Hearts manga, Volume 1) very pushy involving his fight over Kairi, shown when he tells Sora that, if the latter does not share a paopu fruit with Kairi soon, he will. All three of them, as well as the other children that live on the islands, spend most of their time on the smallest island, acting as their own personal playground.
However, things take a drastic turn on the night before their journey. Riku, likely unable to leave the islands without knowing the truth, opens the door in the secret place and the Heartless, beings of darkness, invade the islands, seeking out the world's heart. Both afraid that a storm would destroy the raft, Kairi and Sora each set out for the island to make sure their raft is safe. Sora finds Riku first. However, while Sora is concerned for his friend's safety, Riku is only obsessed with finally escaping the islands. Darkness surrounds the two, and Riku disappears into it, while Sora gains the Keyblade.
Riku eventually ends up in Hollow Bastion via the Corridor of Darkness, separated from his friends. There, he is found by Maleficent and she offered shelter and protection.
In exchange for Riku's cooperation in gathering the Princesses of Heart, she agrees to find Kairi and bring her to him. During this time, Riku comes to possess a blade called Soul Eater. Though Riku is provided a place to stay, Maleficent begins corrupting his mind, convincing him that Sora has replaced him and Kairi with Donald Duck and Goofy. She claims that the only way to save Kairi, who has lost her heart to the darkness, is to ally himself with her and her band of villains, while abandoning Sora. Not long after, he meets Sora in Traverse Town, takes a look at his Keyblade, holds it for a few moments, and gives it back to Sora without it disappearing from his hand - a foreshadowing of Riku's role as a Keyblade wielder. After his reunion with Sora in Traverse Town, Riku begins to agree with Maleficent and officially starts his stay with her. However, he is still highly suspicious of her motives.
As the days progress, Riku becomes steadily angrier at Sora, convincing himself to hate his old friend. He obtains a blade from Maleficent called the Soul Eater and teaches himself to use it, believing it will aid him in his search for Kairi's heart.
With his mind corrupted, Riku meets Sora once again in Monstro, intending to use Pinocchio to help him find a way to save Kairi's heart. However, Pinocchio ends up captured by a giant Heartless called the Parasite Cage, and Riku is forced (somewhat against his own wishes) to work together with Sora, Donald, and Goofy to save him. Afterwards, Riku kidnaps Pinocchio, and is pursued by Sora, Donald, and Goofy into Monstro's stomach. Riku asks Sora to join him and help him rescue Kairi, but Sora refuses, knowing that Riku's methods are wrong. When the Parasite Cage returns, Riku vanishes into a Corridor of Darkness.
Riku later appears at Neverland, traveling on Captain Hook's ship, where Kairi's body is held. Riku also now shows that he has gained the power to control the Heartless, a gift granted to him by Maleficent. He then goes to Sora, revealing that he has Kairi's body in his possession. Sora warns Riku that the Heartless will eventually turn on him and devour his heart, but Riku refuses to listen and retreats after creating AntiSora, a dark reflection of Sora, with his newly acquired dark powers. However, before he heads back to Hollow Bastion, he instructs Captain Hook that the captured Wendy is not a Princess of Heart. Riku takes Kairi and recklessly returns to Maleficent's castle via the Corridors of Darkness without a vessel, a foolish act that strains even his powerful heart. While he is drained from the trip, Maleficent unlocks the last of Riku's power and the boy's heart is plunged into almost complete darkness.
At Hollow Bastion, Sora again meets Riku, and defends the wounded Beast from a swift death by Riku's blade. But the Beast is hardly one of Riku's major concerns, as Riku reveals his true purpose for confronting Sora. He is able to wield the Keyblade. Riku explains that Sora was only a temporary recipient, telling him that he was "just the delivery boy" and that Riku is the true Keyblade master. After leaving Sora with the toy sword he used on Destiny Islands, he departs, and Donald and Goofy follow him as per The King's orders, though regretfully.
Though Sora is significantly weakened, he makes his way to the foyer of the castle with the help of Beast. Riku, having taken on a new appearance with the increasing strength of his dark powers, tells him to quit, but Sora refuses to leave without Kairi. Riku, intending to prove to Sora that he is the strongest of the two, attacks his old friend, only for Donald and Goofy to go to his aid after finding themselves unable to betray Sora after all that they had been through together. With the strength of his friends, Sora regains the Keyblade, becoming the true master, and drives Riku to fight him.
Defeated, Riku manages to escape, but is confused as to why Sora was able to regain the Keyblade. A mysterious voice somehow contacts him from the Darkness, telling him that only one with a stronger heart can claim the Keyblade, and Riku himself was weaker than Sora. However, the mysterious voice, now slowly taking a shape, presents Riku with an offer he can not resist, a Keyblade of his own. Under the influence of jealousy and rage, Riku agrees to become one with the Darkness, only to become possessed by the mysterious voice itself.
The new Riku then presents himself to Maleficent and warns her of the dangers of unlocking the Final Keyhole. When she claims not to be afraid, Riku shows a new, dark Keyblade created with six of the seven princesses' hearts. However, it doesn't react to the Keyhole. Realizing it is still needing Kairi's heart to be complete, Maleficent heads off to handle Sora and co. After Maleficent is defeated by Sora, Riku appears with his Keyblade and explains that unlike Sora's Keyblade, this Keyblade possesses the ability to unlock a person's heart, and Riku demonstrates this by piercing Maleficent's chest, allowing the immense darkness that is attracted to her to overtake her heart, transforming her into a giant dragon. While this form proved a far deadlier enemy to Sora and his friends, it still was defeated and killed. Riku reappears, commenting on how Maleficent was being used by the Heartless before disappearing again.
Riku, calling himself Ansem, the Seeker of Darkness, later confronts and battles Sora (who is cut off from Donald and Goofy) at the Final Keyhole. He hopes to release Kairi's heart from within Sora's, so that she, being the final Princess of Heart, can open the Keyhole. He fails, but Sora impales himself with the Keyblade anyway to save Kairi. With Sora gone, Ansem attacks Kairi, Donald, and Goofy, but they are saved by Riku, who is using the last of his strength to hold the dark powers of his possessor off.
Riku's rejection of Ansem leads to an internal struggle between the two, which Riku ultimately loses. This causes Riku to lose control of his body once more, while Ansem gains it fully.
A newly restored Sora, along with Donald and Goofy, eventually make their way to the End of the World, a world made of the worlds that have been destroyed by the Heartless. There they once again confront Ansem and defeat him after a series of battles at the Door to Darkness.
Riku is then restored, and appears on the other side of the Door to Darkness, aiding Sora in closing it, but unable to cross it, as only pure darkness can go back and forth through the door. Waiting to enter the Realm of Light are thousands upon thousands of Heartless, which only causes further problems for the two friends. However, King Mickey, appearing for the first time in the game, wards them off with the powerful Kingdom Key D. The King and Sora then proceed to close the door, Sora on the outside, Mickey within. Riku is stuck on the other side of the door with the King, but not before he told Sora to "take care of her," meaning Kairi.
- "Neither suits me. I'm taking the middle road."
"Do you mean the twilight road to nightfall?"
"No. It's the road to dawn."
- —Riku and DiZ
Riku awakes in the lowest basement of Castle Oblivion , being led there by his heart resonating with Sora, who also happens to be in Castle Oblivion, though on the ground floor. A dark card and a disembodied voice present themselves. The Voice offers Riku the chance to sleep and forget his troubles as well as the light, or take the card and take the first steps toward the truth. Riku takes the card confidently stating that "This looks like a boring place to take a nap anyway."
Riku arrives in none other than Hollow Bastion, though only a version of it crafted from his memories. However, though Hollow Bastion is the same as he remembered it, he is unable to find anyone. All the while he searches, the Voice speaks to and mocks the young teenager.
At long last, Riku meets someone: Maleficent. Maleficent taunts him and his refusal of the darkness, but Riku fights and defeats her, hoping to prove that he is above the darkness.
Riku leaves Hollow Bastion, only to see the true form of Castle Oblivion. The voice again comes to Riku, but this time reveals himself to be Xehanort's Heartless, who wants to take over Riku again. However, though Xehanort's Heartless is powerful, King Mickey comes to aid Riku with his light. Riku then manages to fend off Xehanort's Heartless for the time being. But before he leaves, the Heartless leaves Riku with some world cards and the ability to wield his inner darkness as a weapon.
Riku soon realizes that he has the power to detect the "smell" of darkness, and is discouraged by it, though King Mickey comforts him. However, King Mickey can only appear to Riku as a projection, for he is still in the Realm of Darkness. Still, with King Mickey's encouragement, Riku ascends the basements of Castle Oblivion in order to rid himself of his darkness. Meanwhile, as Riku travels through the lower levels of Castle Oblivion, Sora ascends the upper floors, being manipulated by Marluxia, a member of the mysterious Organization XIII and the lord of Castle Oblivion. But three other Organization members, Vexen, Lexaeus, and Zexion work to counter Marluxia by using the dark-wielding Riku against the light-wielding Sora.
To further the trio's goals, Vexen independently appears before Riku and the latter wonders if Vexen is with "Ansem" (Xehanort's Heartless). Vexen cryptically responds that he is with "another Ansem". Still, Riku fights against Vexen, seeing him as an enemy. However, the battle only helps Vexen, who uses the data he gathered from the battle to create a replica of Riku. The replica soon comes to battle Riku, mocking Riku's fear of the darkness while the replica embraces it. However, the real Riku proves victorious, and the replica runs off.
Soon, Xehanort's Heartless appears again, saying that the replica is a model of what Riku should be. But Riku only reaffirms his desire to conquer his darkness.
Passing through much of the castle (the bulk of Sora's story is complete, and Larxene and Vexen have been eliminated) Riku finds Lexaeus. Lexaeus, like the others, tells him that he should accept the darkness again, because if he doesn't, his journey will end here. The two fight, and Riku only manages to wear him down. As Riku moves in for the finishing blow, Lexaeus summons herculean strength and knocks Riku unconscious with his Axe Sword. Lexaeus decides to eliminate him since taking him down was too much trouble, but as he does so, he notices Riku becoming possessed by Xehanort's Heartless. This catches Lexaeus off-guard, and the Xehanort-possessed Riku takes the opportunity to kill him. Although Lexaeus is defeated, Riku ends up having a struggle with Xehanort's Heartless that he nearly loses. Just before the dark being can overwhelm Riku, Mickey saves him again and manages to bring him out of the darkness.
Riku comes closer to the ground level, just as Marluxia's scheme fails and Sora finishes him off. Riku senses Marluxia's defeat, and Zexion quickly arrives on the scene to explain it. But he also reveals that Sora is the one who did the deed, much to Riku's surprise. Zexion quickly asks if Riku is capable of seeing Sora, for Riku shouldered the darkness for so long, and Xehanort's Heartless still resides in his heart. Riku tries to resist Zexion's comments, but Zexion ultimately gives him a world card of Destiny Islands.
In Destiny Islands, Riku meets all of his friends, but they are all silent and they eventually disappear, even Kairi. Zexion throws all of Riku's fears at him at once, telling him he's responsible for causing them to disappear, and that he belongs to the darkness now. He finally transforms an illusion of him into a Darkside Heartless, telling him this is what he has become. Riku defeats the Heartless as Zexion disguises himself as Sora. He tells him that it's finally time to face the light.
Riku sinks into the light as he begins to fade, but Naminé appears in the form of Kairi and tells him that he can't fade, because light can't destroy him, and neither can darkness, so he should accept both to drive away his fears. He awakens his dark powers again, admitting that it's a part of him and not evil, defeating Zexion. Zexion disappears, but is quickly killed by the Riku Replica with Axel.
Riku nearly makes it to the main floor as Xehanort's Heartless appears to control him, but King Mickey defends Riku again and finally appears for real. Riku is relieved at finally having a real friend with him. King Mickey explains that he found a card which showed him Riku's heart and he followed it back to him. Riku uses the card, and ends up in Twilight Town. Xehanort's Heartless appears again, but Riku tells him that he's not "Ansem", because his scent is not darkness--but rather something else. Riku also sees that this man is the voice that presented itself at the beginning of his journey. The voice finally appears and introduces himself as DiZ . Riku asks him what he really wants from him, and DiZ tells him he wants him to choose between Light and Darkness, because he lies in-between. The decision will be decided with Naminé, whom Riku looks for.
However, the Riku Replica manages to find him, and demands another fight to prove him "worthy". The replica intends to kill Riku in order to become real, but fails. However, Riku comforts him by saying that the replica's heart will go to the same place as the real one's, before the replica vanishes out of existence.
Riku meets up with Naminé. who is with Sora in his memory pod, and explains the situation. She offers to seal away Xehanort's Heartless and Riku's darkness, so that he may forget them, but will have to sleep to do so. Riku refuses, hoping to win on his own, and leaves a satisfied Naminé. However, before he departs, he tells Naminé that he knows that it was she who appeared to him as Kairi, commenting that they smell the same.
After meeting Naminé, DiZ appears again to Riku and the King (who notes that DiZ seems familiar). Knowing his choice, DiZ gives Riku a card that will draw out Xehanort's Heartless. After DiZ leaves, Riku tells King Mickey to destroy him if he fails to stop Xehanort's Heartless, but the King refuses, saying he'll only help him regain control, and never harm him. Riku concedes.
Riku faces Xehanort's Heartless for one final battle alone. Ansem asks why he still refuses him if he accepts darkness now, and inquires if Riku is still scared of the darkness. Riku denies this and merely says, "I just can't stand your foul stench." They fight and the last of Xehanort's Heartless is destroyed, but not before he says a part of him is still in Riku, and that he shall return.
Riku and Mickey wait at the crossroads. Riku tells him that he can't go home yet, as "Ansem's" shadow still lingers in him, but Mickey says the darkness is a part of him. Darkness is not all bad, because Riku has chosen a road he never thought of before, one of both Light and Darkness. Riku, who now forms an equally strong bond to the King as Sora's friendship to Donald and Goofy, calls Mickey by his name at the King's request, making him the only character to do so in the Kingdom Hearts universe (excluding Queen Minnie).
They leave, taking Organization coats that DiZ gave them prior to confronting Xehanort's Heartless, and DiZ appears for one final question: if he shall take the "road to light" or the "road to darkness". Riku chooses neither, he'll take the middle road, "The road to dawn". Riku and King Mickey eventually made it out of the plains and separate after Riku realized he couldn't completely rid himself of the darkness festering in him. Deciding to return to DiZ and offer his help, Riku dons a blindfold, so that "his eyes couldn't lie" about his darkness which he is preparing to use and wished Mickey not to witness firsthand.
- "You could say I am...the biggest nobody of them all."
- —Riku to Xion
Riku plays an important role in the game's story and is the final boss of the game, as the game ends with the battle between him and Roxas. He also appears as a playable character in multiplayer mode. To unlock him, the player must play story mode up to day 171 and unlock the rank of Agent. He is first seen on the bridge in Beast's Castle where he fights Xion. As a defeated Xion lies on the ground, Riku pulls off her hood and pulls up his blindfold to get a good look at her. When he sees her as Sora, he is shocked and begins questioning her how she is able to use the Keyblade, calling it a sham and worthless. Angered, Xion demands what right he had to say such a thing and attacks him, only to be knocked down single-handedly. Riku then tells her to "find a new crowd." It can also be inferred that Riku still can't forgive himself for stepping into darkness when he told Xion, "You could say I am, the biggest nobody of them all."
After Xion left the Organization, the two stayed away in Castle Oblivion. As Roxas and Axel continue to search for her around the worlds, they finally make contact in Twilight Town. Xion quickly takes her leave and Riku stays behind to distract them.
While cradling Xion in his arms during her nightmare, Riku recalls his conversation with Naminé in the white room about her, discussing what has to be done for Sora to wake up. In addition to being with Xion during her nightmare, he is also in her nightmare alongside Zexion. Xion collapses in pain while hearing the hurtful speech Zexion gave Riku from Chain of Memories. She then turns into Roxas, Riku, and finally Sora. After Xion wakes upon Destiny Islands, she expresses her curiosity about "Sora and that girl he's always with", in which Riku tells her that Kairi is someone very special to Sora. He tells her that she is the reason Sora is unable to wake up because part of his memories are inside of her. Even though Xion is unsure of where she truly belongs and what the right choice is, Riku gives her some time to think about it. He is also seen conversing with DiZ next to the pod Sora sleeps in.
Riku is shown meeting with King Mickey in the forest outside the Old Mansion, where he is in his Ansem, Seeker of Darkness form. The King then calls the Keyblade to him, ready to fight, not knowing who he is. To let the King know it's him, Riku puts his blindfold on, which makes him return to normal, surprising the King. He informs Mickey that he will be fighting an Organization member soon, and may not survive, forcing the King to promise to protect Sora.
Sure enough, Riku sees Roxas in The World That Never Was as the latter attempts to free Kingdom Hearts. After he fights several Neoshadows, Roxas finally spots Riku and pursues him. Riku grabs Roxas's Oblivion Keyblade after a failed attack as he falls down from Memory's Skyscraper. As Riku falls, his memories of Xion flash through his head, becoming increasingly blurry. Riku lands, and Roxas drops down after him depicted in several scenes in Kingdom Hearts and Kingdom Hearts II, including the secret endings of Another Side, Another Story and Deep Dive.
Roxas reveals to Riku his goal of freeing Kingdom Hearts as Xion asked him to, so that he, Xion, and Axel could return to being friends. Riku responds by telling Roxas it won't be long before his memory of Xion completely fades. Angered, Roxas fights Riku and gains the upper hand; however, Riku fights back and knocks Roxas unconscious. Roxas quickly comes to, and grabs back Oblivion. Riku then says, "Come on Sora, I thought you were stronger than that." Roxas naturally responds, quipping, "Get real! Look which one of us is winning!", but is immediately shocked by his own words. Riku confirms this as proof of Roxas's status as Sora's Nobody; angry, Roxas pulls out both Keyblades, shouts "I am me. Nobody else!", and knocks Riku back. Xion quickly tells Riku in his mind, "Riku, please! You have to stop him!" Left with no other choice, Riku realizes if he is to win in the Realm of Darkness, he must submerse himself in the same darkness. He removes his blindfold, taking the form of Ansem, Seeker of Darkness. He quickly dispatches Roxas, and returns him to DiZ's base underneath the abandoned mansion in Twilight Town, introducing himself as "Ansem".
Riku continues to ally himself with DiZ, as they have a common goal: to help Sora awaken (though Riku finds his memories of Sora fading, being a side-effect of Naminé's toying with Sora's memories). DiZ asks Riku to kidnap Roxas, the Nobody of Sora, who has been having trouble regaining his memories. If he and Roxas join, Sora should be able to reawaken. Riku enters the Realm of Darkness, and corners Roxas in The World That Never Was. In their battle, they seem to stalemate, although Roxas manages to strike him back, seemingly crippling Riku's left hand. Xion quickly tells him in his mind, "Riku, please! You have to stop him!" Riku then realizes if he is to win in the Realm of Darkness, he must submerse himself in the same darkness. As a result, Riku unleashed his darkness, taking on the form of Ansem, Seeker of Darkness as a side effect. Riku easily defeated Roxas, and returns him to DiZ's base underneath the abandoned mansion in Twilight Town, introducing himself as "Ansem".
Roxas' memory is erased by DiZ and he is placed into a Simulated Twilight Town, to live out his days until the time comes for him to meet Sora. Meanwhile, Riku watches over Roxas, periodically entering the town in order to keep Roxas ignorant to the truth, including keeping Naminé from saying anything important to Roxas. He also takes some keepsakes of Roxas' during some of his visits. With all these deeds done, Riku finally demands to know what DiZ's true objective is. Upon hearing that it is merely revenge (DiZ does not disclose against whom it is), Riku clenches his fist, shocked and disgusted at how DiZ is merely using him and Sora for selfish reasons.
Eventually, when the time comes for Roxas, Riku makes sure to prevent the Nobodies from flooding the town. Soon, the goal Riku had been searching for is finally reached: Roxas joins with Sora. Though DiZ orders him to eliminate Naminé, Riku desires no part in DiZ's prejudice revenge and hands her to the now-renegade Axel of Organization XIII before leaving DiZ.
Riku, after Roxas joins with Sora, comes into contact with King Mickey. Riku begs King Mickey not to reveal his whereabouts and condition to Sora, and the King reluctantly agrees. He then leaves the King the digital versions of Olette's munny pouch and Roxas' crystal orb that he had pilfered from Roxas earlier.
Later, Axel tries to kidnap Kairi in an attempt to use her to turn Sora into a Heartless so Roxas would be reborn. However, Riku rescues Kairi by opening a Corridor of Darkness, and takes her to Twilight Town, where she meets Hayner, Pence, and Olette, but never reveals his identity. However, Axel again appears, but another member of Organization XIII, Saïx, manages to kidnap Kairi, with the intent to use her to fuel Sora's rage. At the battle for Hollow Bastion, Sora, Donald, and Goofy end up in an empty realm, where Riku arrives. He says nothing to them, and only leaves the trio a box that contains sea-salt ice cream and a picture of Roxas, Hayner, Pence, and Olette in front of the haunted mansion.
Riku also arrives at the Land of Dragons, trying to warn the Emperor of a Heartless dragon that Xigbar created. But he ends up meeting Sora, and Sora attacks him, thinking Riku to be an Organization member. However, Sora sees that Riku is wielding the Soul Eater, and begins to suspect Riku's identity. But Riku still goes ahead with his mission, and warns the Emperor (but had to defeat Li Shang in order to do so). When Sora talks to the Emperor, the wise ruler's description of the man further cemented Sora's idea that the man he fought was Riku.
Riku later appears in the World That Never Was, after Naminé rescues Kairi. The two are faced against Saїx, but Riku quickly comes to the rescue, his Soul Eater having now transformed into a Keyblade called Way to the Dawn. Naminé calls Riku by name, and disappears. Kairi, excited to see Riku, removes his hood, but is met with the face of Xehanort's Heartless. She takes it in stride, seeing the true Riku underneath his current form.
Kairi later is attacked by Heartless on her way to see Sora, being saved by Riku. He then gives Kairi the Destiny's Embrace Keyblade so that she may fight. After Sora defeats Xigbar, he and Kairi reunite. Riku tries to take his leave, but Kairi stops him. She then reveals Riku's identity, and with some concentration, Sora also sees Riku underneath his dark appearance. The revelation makes Sora overjoyed to the point of tears. Riku explains that he did not want to be found, thanks to his appearance, and confirms Sora's suspicions of the clues they found- namely, the ice cream and Roxas' photo. Still, he and the others make their way up the castle, defeating the remaining Organization members save for Xemnas. During this time, Riku reveals the truth about Roxas to Sora, and realizes that he never had to fight him; Roxas had left Organization XIII because he had wanted to meet Sora, and would most likely have met him either way over time.
Near the top, Riku reunites with King Mickey and DiZ, his true name being Ansem the Wise, who is using a machine to try and encode Kingdom Hearts into data. Xemnas also arrives, and he and Ansem the Wise trade bitter words. The machine then explodes, unable to handle Kingdom Hearts, sending Ansem the Wise to the Realm of Darkness while causing countless hearts Xemnas had collected into Kingdom Hearts to rain down on the world, creating a slew of Heartless. The explosion also cleanses Riku's heart and restores Riku to his original form, though he is still remorseful. After some encouragement, Riku transcends the rest of the castle, abandoning his cloak and blindfold. He and the others also encounter Maleficent and Pete, who decide to hold off the hordes of Heartless that are overtaking the castle, but only so that they will eventually take the castle for their own.
Riku and the others then confront Xemnas, refusing his demand to gather more hearts. Xemnas then removes Sora from the area, fighting him one on one, with everyone else calling out to him. When Sora returns, they see that Xemnas has already reached Kingdom Hearts, and disappears into it. A door, constructed by the will of the worlds, appears, and the three wielders of the Keyblade open it up and follow Xemnas. After a tough battle, Naminé appears again, opening up a corridor of darkness that leads to Destiny Islands, as Riku can no longer use them. However, Xemnas attacks, riding on a gigantic robotic dragon, and separates Sora and Riku from the others. After a series of battles, the two of them are drawn into nothingness by Xemnas and face in a final, exhausting battle.
Towards the end after the final attack used by Xemnas, Sora is left open and Riku takes a blow intended to finish off his friend, which allows Sora to finish Xemnas off with both Riku and Sora firing a beam of light from Sora's keyblade. After the fall of Xemnas, Sora and the injured Riku face an onslaught of Dusks ready to fulfill their master's final order: eliminate the Keyblade wielders. However, the Dusks disintegrate back into nothingness, and Sora and Riku escape the realm, entering the Dark Meridian.
Having the time to finally talk, the two reconcile with each other. Riku then comes across a letter in a bottle, written by Kairi, and gives it to Sora, believing him to be the proper recipient. Sora then manages to open the Door to Light, as King Mickey predicted, and the two return home, reuniting with their friends. While Sora shares a hug with Donald and Goofy, Riku shares his own moment with King Mickey. Ironically, even though Riku was once jealous of Sora's friendship with Donald and Goofy, he ended up having a similar one with Mickey.
Some time later, Sora and Riku observe the waves of Destiny Islands, saying that it's a small world but also part of a much bigger one, then jump to discussion about the Door to the Light. Kairi then appears with a letter from the King, the contents obscured from the player's view.
A data version of Riku has a brief appearance in virtual Destiny Islands only to be like he was before anything happened after his world disappeared.
In one of the cutscenes, Xehanort's Heartless and Riku encounter each other right after Sora disappeared to Traverse Town, shortly before Destiny Islands was completely swallowed by the darkness. In the last minute, Xehanort's Heartless opens a portal for Riku, allowing him to enter and arrive in Hollow Bastion.
Later on, the mysterious black coated figure is revealed to be a Data Riku, similar to Data Sora. Riku explains that the Jiminy's Journal chose him as the vessel for the memories in the journal, and in a sense he is the Journal incarnate. In the Data Olympus Coliseum, the Data Riku/Journal says to Data Sora the reason he didn't reveal himself to him earlier is because he wanted Sora to become stronger. He discusses with Sora whether they are data or artificial but the Riku/Journal said it doesn't matter as long as they made an impact to the world and it helps their friends. It is revealed the reason the video kept showing things Jiminy never wrote about is because it shows the Journal's sleeping memories. Even the Riku/Journal incarnate doesn't know the reasons behind the mysterious messages appear in the journal, the Bug Blocks that appear in the Data Worlds, or what is happening to the Data World. When the Journal gets overwhelmed by the Bug Blocks, he falls under the control of Maleficent and fights the protagonists until Sora defeats him.
The real Riku appears at the end of the game with the real Sora and Kairi where they read Mickey's letter. This scene corresponds the final of Kingdom Hearts II.
Afterwards, Sora sits on the Paopu tree while holding the message from King Mickey, staring off into the sunset. He is then confronted by Riku who asks him if he has decided (about what is not specified), and Sora says that he has. Kairi then walks up to him and Sora tells her that everyone is suffering and waiting, and that he has to put back everything that is connected to him, or "Reconnect." She then hands him her lucky charm and tells him to hurry back.
Riku is called to the Mysterious Tower by Yen Sid to undertake the Mark of Mastery Exam along with Sora so that they become storng enough to combat the threat of Master Xehanort's return. However, Riku holds doubts in his heart as he has fallen to darkness before and wonders if he is truly worthy to wield a Keyblade.
For the exam, Riku is sent to the Realm of Sleep along with Sora to wake seven worlds that remained in a deep sleep following the destruction of Xehanort's Heartless, Ansem. As he journeys through the worlds, Riku encounters a strange young man in am Organization XIII coat, who he shockingly finds being accompanied by Ansem himself. When Ansem goads him into giving into the darkness again, Riku defends himself, saying he walks the Road to Dawn.
Eventually, Riku ends up in The World That Never Was, only to find Sora has been put in a illusion to weaken his heart. Trying to wake his friend, Riku fights off a Nightmare created from Sora's darkness. Victorious, Riku is pulled into darkness by Ansem, who tries getting him to join with him again. However, Riku declines and learns that he has actually been in Sora's dreams the whole time; he is transported to the true Dreaming Realm afterwards.
With Mickey's help, Riku breaks into Where Nothing Gathers and fights off Young Xehanort in an attempt to rescue Sora. However, this revives Master Xehanort. Riku is the pinned down by Ansem whil King Mickey is held down by Xemnas. If if were not for the arrival of Donald, Goofy and Lea, Sora would have been made into the thirteenth heart of darkness Xehanort needed for the X-blade's creation. Riku then enters Sora's heart and gathers it's fractured pieces before freeing him from Ventus's possessed Keyblade Armor. Successful, Riku is declared as Keyblade Master and is very surprised to learn that Lea is now a wielder as well.
Riku is then sent to Destiny Islands to retrieve Kairi on Yen Sid's orders. When they arrive, Riku learns that they are to train her to use the keyblade she inherited from Aqua years ago to combat the new Organization XIII.